S'pore device makes the cut in twins operation

S'pore device makes the cut in twins operation

SINGAPORE (Reuters): Singapore developed technology, which offered surgeons virtual and real medical models for practice, was vital to the rare successful separation of a pair of Nepali twins earlier this month.

A team of 20 specialists separated 11-month-old Ganga and Jamuna Shrestha -- who were joined at the head and had two brains intertwined in one skull -- on April 10 after almost four days in surgery.

"The greatest difficulty in this case was to understand the anatomy of the brains," Keith Goh, the pediatric neurosurgeon who led the marathon operation, told Reuters in an interview on Monday.

"The virtual reality computer system enabled us to appreciate the three-dimensional reconstruction based on the (two- dimensional) scans we had done ... that was critical to our assessing, understanding the brains and the decision of whether we could separate them or not."

Goh and his team rehearsed the operation several times with a three-dimensional imaging device and software developed by local company Volume Interactions -- a spinoff from a government research institute.

The device, called a dextroscope, comprised a computer monitor and a mirror suspended in a frame. Specialized software fused a variety of 2-D scans into a virtual object.

Doctors, with the use of 3-D glasses, stylus and mouse could "operate" on the girl's brains.

While a lot of companies offer 3-D medical images, none of them allow doctors to physically interact with the images, Peter Munzel, Volume Interactions' chief executive officer said.

The device allowed doctors to have a more realistic image of the twin's anatomical structure and discover new elements which did not appear in 2-D images, Munzel said.

An American neurosurgeon had used a prototype of the dextroscope and accompanying software in 1997 to successfully separate a pair of Zambian brothers joined at the head.

Singapore doctors also employed life-sized models of the twin's skin, skull, blood vessels and brains which Goh said were essential to helping doctors better understand the girls' anatomy.

The models were created at Nanyang Polytechnic with the help of commercially available software which local engineers optimized, and rapid prototyping machines normally used to create telecommunication devices, Teddy Ong, manager of the polytechnic's Rapid Prototyping Center said.

The engineers who also used 2D images as raw data, were faced with the challenge of segmenting the data accurately.

"When you import this data, everything is shown on the screen; you see soft tissues, cartilage, bones, the brain," Ong told Reuters. "It's important that the segmentation is done correctly ... to make precise, customized models for such complex applications."

Singapore has pumped billions of dollars into its efforts to become an Asian hub for the biomedical sciences with its sights set on nurturing local talent and attracting world-class companies to its shores.

"Our technology is world-class. It was home grown, used in this case by our own doctors, and credit has to go to all workers who made it possible," said Goh who was optimistic about the twin's condition.

Optimistic

The Singapore surgeon was optimistic about their condition on Monday, even as one of the girls was wheeled from the operating theater after more skin grafts.

Doctors discovered last Saturday that the skin graft on the left part of Jamuna's scalp had not healed well. Plastic surgeons were called in to operate on Sunday.

"They have achieved a reasonable closure (of the scalp) this time," Keith Goh, the pediatric neurosurgeon who led the original procedure, told Reuters in an interview on Monday.

"We know that her brain is quite intact with no evidence of infection in the brain and that's why the scalp cover has to be maintained."

Goh said Jamuna was already stirring from the operation which ended early on Monday morning. Her sister Ganga's head wounds were healing well despite a serious infection.

"She seems to be showing signs of turning the corner. Her fever is beginning to settle down," Goh said. "Her brain functions are coming back in the sense that she's more alert. Her ventilator requirements are really very minimal."

Ganga remains on a respirator as her infection demands frequent dressing changes and draining of fluids. Jamuna has been breathing on her own since April 17.

Better

"As we go on further and further away from the end of the operation, the potential for recovery gets better," Goh said.

The two weeks since the surgery had been "pretty stormy" with doctors' attention swinging from one twin to the other, he said.

Ganga initially was more responsive but was found to have a more severe infection last week. Jamuna was slower to wake and was faced with an enlarged liver and lung congestion but had been bottle-feeding even before Sunday's skin-graft operation.

Doctors will be able to gauge how well the twins' brains are functioning only after the infections subside but they remain optimistic as both babies can move their arms and legs, indicating there was no severe paralysis, Goh said.